diff --git a/archive/hugo/content/resources.md b/archive/hugo/content/resources.md index 35cba6e..00e05f6 100644 --- a/archive/hugo/content/resources.md +++ b/archive/hugo/content/resources.md @@ -52,6 +52,8 @@ Recently, I've been... | Name | Progress | | --- | --- | +| [獵魔士](https://www.netflix.com/hk/title/80189685) | +| [](https://baike.baidu.com/item/罗小黑战记/22902442) | | [罗小黑战记](https://baike.baidu.com/item/罗小黑战记/22902442) | | [哪吒之魔童降世](https://movie.douban.com/subject/26794435//) | | [中国机长](https://movie.douban.com/subject/30295905/) | diff --git a/archive/hugo/content/tools.md b/archive/hugo/content/tools.md index f70f1ec..415260b 100644 --- a/archive/hugo/content/tools.md +++ b/archive/hugo/content/tools.md @@ -34,3 +34,9 @@ menu = "main" ### iOS - [Infuse](https://firecore.com/infuse):视频播放 + +## 网站 + +### 下载 + +- [Old version](http://www.oldversion.com):下载软件历史版本 \ No newline at end of file diff --git a/source/_posts/daily-trivials.md b/source/_posts/daily-trivials.md index 0f8208d..2158400 100644 --- a/source/_posts/daily-trivials.md +++ b/source/_posts/daily-trivials.md @@ -8,6 +8,12 @@ draft: false 这篇文章讲用于记录我日常遇到的一些问题的解决和一些小的hacks。话不多说,let's begin. + +- start zookeeper error: ERROR Unexpected exception, exiting abnormally (org.apache.zookeeper.server.ZooKeeperServerMain) +java.io.IOException: No snapshot found, but there are log entries. Something is broken! + +手动删除掉zookeeper下的数据后可以正常启动 `rm -rf /usr/local/var/lib/zookeeper` + - nginx测试配置是否正确 The -c flag indicates a certain configuration file will follow; the -t flag tells Nginx to test our configuration. @@ -38,9 +44,9 @@ chmod 777 /tmp/.X11-unix/X1 brew install kafka ``` To have launchd start kafka now and restart at login: - `brew services start kafka` + brew services start kafka Or, if you don’t want/need a background service you can just run: - `zookeeper-server-start /usr/local/etc/kafka/zookeeper.properties && kafka-server-start /usr/local/etc/kafka/server.properties` + zookeeper-server-start /usr/local/etc/kafka/zookeeper.properties && kafka-server-start /usr/local/etc/kafka/server.properties - 误删macOS唯一一个administrator的用户admin组,不小心使用了`sudo dseditgroup -o edit -a $(whoami) -t user admin` (本意只是想从wheel组里面删掉)命令把系统上唯一一个具有超级管理员权限的用户的组权限给删了,导致使用sudo命令会提示 `$(user) not in sudoers file, this incident will be reported....` diff --git a/source/_posts/leetcode-7-reverse-integer-md.md b/source/_posts/leetcode-7-reverse-integer-md.md new file mode 100644 index 0000000..1e4f10c --- /dev/null +++ b/source/_posts/leetcode-7-reverse-integer-md.md @@ -0,0 +1,67 @@ +--- +title: leetcode-7-reverse-integer.md +tags: ["leetcode", "solution"] +date: 2019-11-26 20:56:46 +--- + + 7. Reverse Integer + Given a 32-bit signed integer, reverse digits of an integer. + Example 1: + + Input: 123 + Output: 321 + Example 2: + + Input: -123 + Output: -321 + Example 3: + + Input: 120 + Output: 21 + + Note: + Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231, 231 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows. + + + +题意很简单,就是数字反转,例如123-\>321。解法也比较简单,就是每次取除10的模数(然后除10取整),原数乘10累加。例如123就是1+10*((0+3)*10+2)=321。需要注意有两个点,一个是可能数字是120000,那么就不能简单地通过字符串反转来做(算数方法做是没问题的);另一个就是有边界,边界是4字节的有符号整型数字的范围,也就是 $$[-2^{-31}, 2^{31}-1]$$。 + +我的做法比较粗暴,判断还有一位的时候用边界去减了除10,和当前数比较大小即可(其实这么做有问题,如果test case长度不是2的31次方位,比如100位的数字,那也会最后一步才会判断是否溢出,对于python这种科学计算型语言不会有问题,因为底层已经处理了大数运算。对于C、Java等传统语言,这么写就会有问题。当然,也可以上来就手动判一下数字长度,如果大于10就直接返回0,不过我没写。),也没想到居然这么写过了,代码如: + +```python +class Solution: + def reverse(self, x: int) -> int: + n = 0 + flag = 1 + if x < 0: + flag = -1 + x = -x + while x > 0: + if x < 10: + if flag == 1 and n > ((1<<31)-1-x)/10 or flag == -1 and n > ((1<<31)-1)/10: + return 0 + n = n * 10 + x % 10 + x = x // 10 + return flag * n +``` + + + +然后就是参考题解了。发现有两个地方可以改进代码。一个其实不用一开始就把负数转换为正数,因为带符号数累加之后符号还是在的;还有一个是判断条件可以做修改为判断为当前数是不是大于MAXINT/10,因为如果大于的话那么下一次x10就必然溢出;如果等于那么判断尾数是不是大于等于8(正数时)、小于等于-9(负数时)。 + + + + + + + + + + +# Refer + +[7. Reverse Integer](https://leetcode.com/problems/reverse-integer/) + +[7. Reverse Integer](https://leetcode.com/articles/reverse-integer/) + +# Appendix \ No newline at end of file